1. Field of the Invention
The present invention relates to a starting control device of an electric vehicle. More particularly, to the starting control device of an electric vehicle including a high voltage main battery for supplying electric power to an electric motor (hereinafter referred to simply as a “motor”), which is a driving source of the vehicle, and a low voltage sub-battery for supplying electric power to electric power driving devices (auxiliaries) except the motor provided in the vehicle.
2. Description of Background Art
Generally an electric vehicle includes a high voltage main battery for supplying electric power to a vehicle traveling motor and a low voltage sub-battery for supplying electric power to on-vehicle devices except the motor. High tension power from the main battery is converted to low tension by an electric power converter (DC-DC converter), and supplied to the sub-battery, thereby charging the sub-battery. On the other hand, in the configuration where a vehicle drive control unit is driven by the electric power from the sub-battery, when the capacity of the sub-battery decreases, even if the capacity of the main battery is enough, the vehicle drive control unit cannot be started, so that the vehicle cannot be operated.
In the electric vehicle described in JP-A-2002-209301, when a vehicle drive control unit (a high rate controller) cannot be started due to a decrease in the capacity of the sub-battery, the so-called jump starting is enabled by applying a starting voltage to the high rate controller from an external power supply device through a cigar lighter socket.
In the electric vehicle described in JP-A-2002-209301, when the residual capacity of the sub-battery is small, a jump starting can be enabled without any supply of electric power from the sub-battery. However, the cigar lighter socket as an external power supply means is used only for the jump starting, not used for charging the main battery. In the hybrid vehicle including an internal combustion engine as a power generation means, a battery charger for charging the main battery by an external power supply device is not needed, but in a pure electric vehicle (Pure-EV), a battery charger for charging the main battery by an external power supply device is needed.
Therefore, if the technique for charging the sub-battery by an external power supply device as described in JP-A-2002-209301 is adopted, both the battery charger of the main battery and the electric power supply device (the cigar lighter socket) for the jump starting are needed. This results in an increase in the number of parts.